https://github.com/Norbyte/lslib
This Blender Importer/ Exporter has a well known issue with the LODs.
If you export a model from the game, edit it, whether you create the LODs yourself, or re-export the file with the default LODs, they LOD models will display incorrectly in-game after export.
It seems to be a UV Map/ Texture assignment glitch with the GR2 data.
1st LOD level where there's an issue:


Go even further and you get this issue:


The visuals of the bug changing between each GR2 export is interesting.
Here's how the LODs for Shadowheart are laid out in Blender:

Recommended Export Order:


Example of the objects that display at LOD2 distance level:

There's also some issues with the Importing & Exporting when it comes to body Armature, meaning that you can't edit a GR2 that has already been edited. You have to use the default files that were extracted from the game using the Multitool.
So it seems like this tool is better able to accurately transfer/ convert GR2 files.
https://github.com/ShinyHobo/BG3-Modders-Multitool
